Networks and Internet Protocol
There are many types of computer networks, with the Internet having the most notoriety. The Internet is a worldwide network of computer networks. Today, the Internet is a public and self-sustaining network that is available to many millions of users. The Internet uses a set of communication protocols called TCP/IP (i.e., Transmission Control Protocol/Internet Protocol) to connect hosts. The Internet has a communications infrastructure known as the Internet backbone. Access to the Internet backbone is largely controlled by Internet Service Providers (ISPs) that resell access to corporations and individuals.
With respect to IP (Internet Protocol), this is a protocol by which data can be sent from one device (e.g., a phone, a PDA [Personal Digital Assistant], a computer, etc.) to another device on a network. There are a variety of versions of IP today, including, e.g., IPv4, IPv6, etc. Each host device on the network has at least one IP address that is its own unique identifier.
IP is a connectionless protocol. The connection between end points during a communication is not continuous. When a user sends or receives data or messages, the data or messages are divided into components known as packets. Every packet is treated as an independent unit of data.
In order to standardize the transmission between points over the Internet or the like networks, an OSI (Open Systems Interconnection) model was established. The OSI model separates the communications processes between two points in a network into seven stacked layers, with each layer adding its own set of functions. Each device handles a message so that there is a downward flow through each layer at a sending end point and an upward flow through the layers at a receiving end point. The programming and/or hardware that provides the seven layers of function is typically a combination of device operating systems, application software, TCP/IP and/or other transport and network protocols, and other software and hardware.
Wireless Networks
Wireless networks can incorporate a variety of types of mobile devices, such as, e.g., cellular and wireless telephones, PCs (personal computers), laptop computers, wearable computers, cordless phones, pagers, headsets, printers, PDAs, etc. For example, mobile devices may include digital systems to secure fast wireless transmissions of voice and/or data. Typical mobile devices include some or all of the following components: a transceiver (i.e., a transmitter and a receiver, including, e.g., a single chip transceiver with an integrated transmitter, receiver and, if desired, other functions); an antenna; a processor; one or more audio transducers (for example, a speaker or a microphone as in devices for audio communications); electromagnetic data storage (such as, e.g., ROM, RAM, digital data storage, etc., such as in devices where data processing is provided); memory; flash memory; a full chip set or integrated circuit; interfaces (such as, e.g., USB, CODEC, UART, PCM, etc.); and/or the like.
Wireless LANs (WLANs) in which a mobile user can connect to a local area network (LAN) through a wireless connection may be employed for wireless communications. Wireless communications can include, e.g., communications that propagate via electromagnetic waves, such as light, infrared, radio, microwave. There are a variety of WLAN standards that currently exist, such as, e.g., Bluetooth, IEEE 802.11, and HomeRF.
By way of example, Bluetooth products may be used to provide links between mobile computers, mobile phones, portable handheld devices, personal digital assistants (PDAs), and other mobile devices and connectivity to the Internet. Bluetooth is a computing and telecommunications industry specification that details how mobile devices can easily interconnect with each other and with non-mobile devices using a short-range wireless connection. Bluetooth creates a digital wireless protocol to address end-user problems arising from the proliferation of various mobile devices that need to keep data synchronized and consistent from one device to another, thereby allowing equipment from different vendors to work seamlessly together. Bluetooth devices may be named according to a common naming concept. For example, a Bluetooth device may possess a Bluetooth Device Name (BDN) or a name associated with a unique Bluetooth Device Address (BDA). Bluetooth devices may also participate in an Internet Protocol (IP) network. If a Bluetooth device functions on an IP network, it may be provided with an IP address and an IP (network) name. Thus, a Bluetooth Device configured to participate on an IP network may contain, e.g., a BDN, a BDA, an IP address and an IP name. The term “IP name” refers to a name corresponding to an IP address of an interface.
An IEEE standard, IEEE 802.11, specifies technologies for wireless LANs and devices. Using 802.11, wireless networking may be accomplished with each single base station supporting several devices. In some examples, devices may come pre-equipped with wireless hardware or a user may install a separate piece of hardware, such as a card, that may include an antenna. By way of example, devices used in 802.11 typically include three notable elements, whether or not the device is an access point (AP), a mobile station (STA), a bridge, a PCMCIA card or another device: a radio transceiver; an antenna; and a MAC (Media Access Control) layer that controls packet flow between points in a network.
In addition, Multiple Interface Devices (MIDs) may be utilized in some wireless networks. MIDs may contain two independent network interfaces, such as a Bluetooth interface and an 802.11 interface, thus allowing the MID to participate on two separate networks as well as to interface with Bluetooth devices. The MID may have an IP address and a common IP (network) name associated with the IP address.
Wireless network devices may include, but are not limited to Bluetooth devices, Multiple Interface Devices (MIDs), 802.11x devices (IEEE 802.11 devices including, e.g., 802.11a, 802.11b and 802.11 g devices), HomeRF (Home Radio Frequency) devices, Wi-Fi (Wireless Fidelity) devices, GPRS (General Packet Radio Service) devices, 3G cellular devices, 2.5G cellular devices, GSM (Global System for Mobile Communications) devices, EDGE (Enhanced Data for GSM Evolution) devices, TDMA type (Time Division Multiple Access) devices, or CDMA type (Code Division Multiple Access) devices, including CDMA2000. Each network device may contain addresses of varying types including but not limited to an IP address, a Bluetooth Device Address, a Bluetooth Common Name, a Bluetooth IP address, a Bluetooth IP Common Name, an 802.11 IP Address, an 802.11 IP common Name, or an IEEE MAC address.
Wireless networks can also involve methods and protocols found in, e.g., Mobile IP (Internet Protocol) systems, in PCS systems, and in other mobile network systems. With respect to Mobile IP, this involves a standard communications protocol created by the Internet Engineering Task Force (IETF). With Mobile IP, mobile device users can move across networks while maintaining their IP Address assigned once. See Request for Comments (RFC) 3344. NB: RFCs are formal documents of the Internet Engineering Task Force (IETF). Mobile IP enhances Internet Protocol (IP) and adds means to forward Internet traffic to mobile devices when connecting outside their home network. Mobile IP assigns each mobile node a home address on its home network and a care-of-address (CoA) that identifies the current location of the device within a network and its subnets. When a device is moved to a different network, it receives a new care-of address. A mobility agent on the home network can associate each home address with its care-of address. The mobile node can send the home agent a binding update each time it changes its care-of address using, e.g., Internet Control Message Protocol (ICMP).
In basic IP routing (i.e. outside mobile IP), typically, routing mechanisms rely on the assumptions that each network node always has a constant attachment point to, e.g., the Internet and that each node's IP address identifies the network link it is attached to. In this document, the terminology “node” includes a connection point, which can include, e.g., a redistribution point or an end point for data transmissions, and which can recognize, process and/or forward communications to other nodes. For example, Internet routers can look at, e.g., an IP address prefix or the like identifying a device's network. Then, at a network level, routers can look at, e.g., a set of bits identifying a particular subnet. Then, at a subnet level, routers can look at, e.g., a set of bits identifying a particular device. With typical mobile IP communications, if a user disconnects a mobile device from, e.g., the Internet and tries to reconnect it at a new subnet, then the device has to be reconfigured with a new IP address, a proper netmask and a default router. Otherwise, routing protocols would not be able to deliver the packets properly.
Quality of Interfaces
A number of approaches are available that compare the qualities of the interfaces based on a very narrow set of criteria such as radio signal strength or signal to noise ratios. However, these approaches limit their comparison to the radio network.
Using end-to-end path quality comparisons to select optimal paths has been studied in Reference [6], incorporated herein below, in the context of MPLS (Multi-protocol Labal Switching) networks, where a centralized decision is made on optimal routes to connect traffic sources and destinations. Furthermore, the end-to-end path quality comparisons are used within a single autonomous domain, where the network operator typically has access to all the required statistics. However, these statistics are hard to estimate for an individual mobile. Therefore, such methods are not suitable for an individual multi-interface (mobile) host to compare the qualities of its interfaces in real time.
In addition, techniques are currently available for estimating the available bandwidth, delay or jitter along a network path and may be used to estimate these parameters for multiple interfaces and then compare them (see Reference [10] incorporated below). However, these techniques typically require the device to send a large number of probe packets resulting in long delays and significant waste of scarce wireless network resources; hence, they are not suitable for wireless devices.
The following background references show, among other things, some background technologies related to comparing qualities of interfaces, all of which references are incorporated herein by reference in their entireties as though recited herein in full.
[1] V. J. Ribeiro et al. “pathChirp: Efficient Available Bandwidth Estimation for Network Paths”, PAM Workshop, 2003.
[2] M. Jain, C. Dovrolis, “End-to-End available bandwidth: measurement methodology, dynamics, and relation with TCP throughput,” Proceedings of ACM SIGCOMM, 2002.
[3] B. Melander, M. Bjorkman, P. Guningberg, “A new end-to-end probing and analysis method for estimating bandwidth bottlenecks,” Global Internet Symposium, 2000.
[4] K. Lai, M. Baker, “Measuring link bandwidth using a deterministic model of packet delay”, ACM SIGCOMM, Aug. 2000.
[5] N. Hu, P. Steenkiste, “Evaluation and Characterization of Available Bandwidth Probing Techniques”, IEEE Journal of Selected Areas in Comm., Vol. 21, No. 6, Aug. 2003, pp. 879-894.
[6] T. Anjani et al., “A New Path Selection Algorithm for MPLS Networks Based on Available Bandwidth Estimation”, QofIS/ICQT 2002, LNCS 2511, pp. 205-214, 2002.
[7] T. Anjani et al., “ABEst: An Available Bandwidth Estimator within an Autonomous System.”, Proceedings Globecom 2002.
[8] B. K. Gosh, P. K. Sen, “Handbook of Sequential Analysis”, Marcel Dekker, NY, 1991.
[9] H. R. Neave, P. L. Worthington, “Distribution Free Tests”, Unwin Hyman, London, 1988.
[10] R. S. Prasad, M. Murray, C. Drovolis and K. Claffy, “Bandwidth estimation: metrics, measurement techniques, and tools”, IEEE Network, 2004.
[11] S. Saroiu, P. K. Gummadi, S. D. Gribble, “SProbe: A Fast Technique 'for Measuring Bottleneck Bandwidth in Uncooperative Environments”, Proceedings IEEE Infocom, 2002.
[12] H. Kaaranen et al. “UMTS Networks: Architecture, Mobility and Services”, Wiley, 2001.
[13] V. K. Garg, “IS-95 CDMA and cdma2000: Cellular/PCS Systems Implementation”, Prentice-Hall, 2000.
While a variety of communication systems and methods are known, there remains a need for improved and enhanced systems and methods for communicating over the Internet and/or other networks. Among other things, while there has been work done in the area of physically tracking devices and people, existing systems do not allow, inter alia, messages to be directed to particular locations and not to other locations.